Things new engineers don't know, but should: 1. HR doesn't work for you; they work to minimize liability for the company. If HR thinks the best way to accomplish that is to destroy your life, that's exactly what they will do. 2. Many SV companies, as well as groups within large, respected SV companies, only survive through exploitation. They exploit their customers, their workforce, or both. Exploitation means obtain…
Eventually the one making the promises will either not be around or find that they don't have the resources to fulfill the promise. They may quit when they figure this out, if they haven't already been let go once they've established their status as scapegoat.
If something matters to you, make sure you get the new bosses to announce it in front of people. Be aware that you should have already thought at least briefly about the wording of your resignation letter prior to doing this.